In this work, Y-, Ce- and Tb-doped Si3N4 nanowires have been successfully synthesized by directly nitriding-doped nanocrystalline silicon powders obtained by cryomilling. The obtained single-crystalline alpha-Si3N4 nanowires are nearly 20-50 nm in diameter and up to several micrometers in length. The photoluminescence properties of doped Si3N4 nanowires have also been investigated. The Y-doped Si3N4 nanowires exhibit the main peak at 425 nm, Ce-doped Si3N4 nanowires show a narrow emission peak at 450 nm, and Tb-doped Si3N4 nanowires present a strong and sharp emission peak at 545 nm. Combining with our previous works on Al-, La- and Eu-doped Si3N4 nanowires, the effects of dopants with different valence electron configurations on the photoluminescence properties have been explored. The present study provides a guide to fabricate Si3N4-based nanomaterials for different photonic applications.